He lectured at Essex until 1987, when he left to work full-time on MUD (known as MUD2 in its present version). Recently he has returned to the university as a part-time professor and principal teaching fellow in the Department of Computing and Electronic Systems, supervising courses on computer game design as part of the department's degree course on computer game development.[3]

In 2003, he wrote Designing Virtual Worlds, a book about the history, ethics, structure, and technology of massively multiplayer games.

Bartle did research on player personality types in virtual worlds. In Bartle's analysis, players of virtual worlds can be divided into four types: achievers, explorers, socializers and killers.[4] This idea has been adapted into an online test generally referred to as the Bartle Test,[5] which is quite popular, with scores often exchanged on massively multiplayer online games forums and networking sites.[6]

Circa 2003, Bartle was reported as living in a village near Colchester, England, with his wife Gail and their two children Jennifer and Madeleine.[7]